The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

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The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

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Fair Value Measurements (Other Financial Instruments) (Details) (USD $)			6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011 Equity Securities [Member]	Jun. 30, 2012 Stock Options [Member]	Jun. 30, 2012 Quoted Prices in Active Markets (Level 1) [Member]	Dec. 31, 2011 Quoted Prices in Active Markets (Level 1) [Member]	Feb. 14, 2007 9.75% Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross realized gains, sale proceeds			$ 2,500,000	$ 230,000
Interest rate of senior notes							9.75%
Senior Notes and note payable, fair value	278,500,000	273,000,000			278,400,000	272,900,000
Senior Notes and note payable, book value	$ 275,100,000	$ 275,100,000